S-99291A380 9/16"-12 Locknuts

Key Features & Benefits at a Glance

• Superior vibration resistance through top lock distorted thread design that maintains clamp force in high-stress environments
• Enhanced corrosion protection with black-oxide steel finish for extended service life in industrial conditions
• Reliable performance meeting ASTM Grade C specifications for consistent strength and durability
• Quick installation with standard external hex drive and coarse UNC threading for efficient assembly
• Precise thread engagement with Class 2B fit ensuring secure fastening without cross-threading risks
• Environmental compliance with REACH and RoHS 3 standards for safe industrial usage
• Optimal sizing at 7/8" width and 31/64" height for standard wrench compatibility and space-efficient applications

Professional Applications & Engineering Value

This heavy-duty locknut addresses critical vibration-induced loosening challenges in industrial machinery, construction equipment, and automotive assemblies. The top lock distorted thread technology creates permanent friction along the mating surface, effectively resisting rotational forces that compromise joint integrity. Manufactured from black-oxide steel, the nut provides superior corrosion resistance while maintaining the mechanical properties required for ASTM Grade C applications. The 9/16"-12 UNC coarse thread configuration ensures rapid installation and removal, while the external hex drive accommodates standard tools for maintenance efficiency. Ideal for vibration-resistant fastening in heavy equipment, structural connections, and high-load mechanical systems where reliability cannot be compromised.

Specification Summary & Compliance

This locknut features Class 2B thread fit per UNC standards, ensuring precise dimensional accuracy and reliable mating with corresponding male threads. Manufacturing complies with ASTM Grade C specifications for mechanical properties and performance requirements. The product is fully compliant with REACH (EC 1907/2006) regulations and RoHS 3 (2015/863/EU) directives, confirming adherence to environmental and safety standards for industrial components. Dimensions include 9/16"-12 UNC coarse threading, 7/8" hex width, and 31/64" height for standardized application across industrial fastening systems.